Iceland is beginning to rise as glaciers melt, new research from the University of Arizona (UA) reveals.
A network of 62 global positioning devices placed around the island nation revealed land is starting to rebound as the weight of ice on the surface is relieved. The equipment is capable of detecting movements as small as 1/25 of an inch each year. What researchers found was that the surface of Iceland is rising as quickly as 1.4 inches each year. That movement began roughly 30 years ago, as the region began to experience significant warming.
"Our research makes the connection between recent accelerated uplift and the accelerated melting of the Icelandic ice caps," Kathleen Compton, a doctoral student at the University of Arizona, said.
The idea that land rises as glaciers and other ice formations melt is not a new one. However, this study is the first to find evidence that accelerated uplift is connected to faster melting. The study also examined whether the rise of land on the island is the result of deglaciation in the past, or modern loss of ice formations. Some of the temperature records for Iceland used in the study date back to the 19th Century, and researchers have noted increasing rates of ice loss since 1995.
Data from the global positioning systems revealed that uplifting is occurring at an increasing rate. Mathematical analysis showed that this movement could only be caused by accelerated losses of glaciers. This loss also correlated closely with the rise in temperatures seen since 1980.
"I was surprised how well everything lined up. There's no way to explain that accelerated uplift unless the glacier is disappearing at an accelerated rate," Richard Bennett, a geoscientist with UA, said.
Accelerated land rise was first noted by Bennett in 2013, found within data recorded at a single station near the center of Iceland. The researcher and his team examined nearby stations, to see if they showed a similar result, which they found. That lead the team to determine the cause of the uplift. What they found was that the largest changes in land height were in areas furthest from ice caps, suggesting loss of the icy deposits is driving the change in the altitude of land.
Analysis of ice loss over large areas are difficult to measure. Researchers in this study hope that their investigation will assist in the development of new methods of measuring ice loss through measuring the rise in land formations.
When Iceland last experienced a significant deglaciation, 12,000 years ago, the process fed volcanoes around the island, and many became 30 times more active than normal.
Analysis of the rise of land in Iceland will be published in an upcoming issue of the journal Geophysical Research Letters.
